1. Field of the Invention
The present invention relates to a treadmill for wheelchairs that is designed to help a person or occupant on a wheelchair learn how to operate the side wheels on the wheelchair, to permit the person on the wheelchair to practice physical muscular training and other like exercise motions, and to practice rehabilitating exercises and the like. More particularly, the present invention relates to a treadmill for wheelchairs that is designed to permit a person or occupant on a wheelchair to adjust the mechanical resistance or load to be applied against the rotary motion of the treadmill rollers on which the wheelchair's side wheels are supported, to permit him or her on the wheelchair to adjust the angle of inclination of the treadmill rollers according to any variation in the angle of inclination for the wheelchair wheels, and to permit the wheelchair to be supported on the treadmill with safety, reliability and stability during training and other exercises on the wheelchair. Thus, the treadmill for wheelchairs provided by the present invention allows the user of the wheelchair to practice training and do other exercises on the treadmill while staying on the wheelchair without having to move his or her wheelchair to another location in the room.
2. Description of the Prior Art
A conventional indoor exercising platform on which a person or occupant on a wheelchair can practice training or do other exercise is known which provides variable mechanical resistance or load to be applied against the rotary motion of the treadmill rollers on which the wheelchair's side wheels are supported (Japanese patent application as now published for public inspection under unexamined publication No. 7-255383). Another conventional so-called trainer for wheelchairs is also known which includes a separate device that provides a load to be selectively applied against the rotary motion of the sets of rollers on either side on which the wheelchair's wheels are supported, thereby allowing the user on the wheelchair to operate either of the side wheels for training with stability (Japanese patent application as now published for public inspection under unexamined publication No. 7-299095).
The exercising platform as firstly mentioned above may allow for the adjustment of the resistance or load to be applied against the rotary motion of the rollers on which the wheelchair wheels are supported, but it has several problems yet to be solved. For example, when the load to be applied against the rotary motion of the rollers is provided by friction, the inertial force may be lost. For the trainer including the separate device for providing the load to be applied against the rotary motion of the rollers, as secondly mentioned above, the device must be provided as an external device, which requires extra floor space and which also complicates the mechanical construction.
Specifically, the problems associated with the exercising platform that remain yet to be solved include making the wheelchair wheels unstable on the rollers during the actual training exercise, making it difficult or impossible to adjust the angle between the roller shaft on the platform and the wheel shaft on the wheelchair, and making it difficult to guide the wheelchair wheels onto the platform. More specifically, if it is difficult or impossible to adjust the angle of inclination of the roller shaft with regard to the wheel shaft when the latter is inclined during the training exercise, and thus the wheelchair becomes unstable, and its side wheels might slip out of the rollers.
Furthermore, the exercising platform has another problem yet to be solved in that there is no means for controlling the means for adjusting the resistance or load to be applied against the rotary motion of the rollers.
The trainer which permits the user of the wheelchair to conduct the training exercise by operating either of the side wheels has some problems yet to be solved, with particular regard to the stability of the wheelchair wheels on the treadmill rollers and the ease of controlling the various adjusting means.